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R. 0. COLQUHOUN.

PROCESS FOR BUST PROOFING IRON AND STEEL. APPLICATION FILED MAR. 31. I9I9.

I V i l8 5 g g 5 50 g *E $2 rlplllplplllllpall avwamtoz Patented July 29, 1919.

, TED STATES ROY ID. COLQUHQUN, OF DETROIT, MICHTGAN, ASSIGN OR' T0 PARKER RUST-PROOF COMPANY OF AMERICA, OF DETROIT, MICHIGAN, A GORFORATTON 0F MICHI- I GAN.

PROCESS FOR RUST-PROOFING IRON AND STEEL.

Patented July 29;, was.

Application filed March 31, 1919. Serial No. 286,383.

To all whom it may concern: Be it known that 1", ROY

Improved Process for- Rust-Proofing Iron and Steel, of which the following is a specification.

This invention relates to the art of changing the surfaces of articles of iron and steel from the metallicstateto that of an iron conipound, preferably a phosphate, which point and continually adding in a solution the chemicals necessary to revive the bath as fast as it becomes weakened through use,

the amount of the solution being suilficient to replace that which evaporates.

This process also consists in mlxing the active chemicals in solution in a separate.

tank and drawingofl the solution at the "top so as to leave thesediment at the bottom of the mixing tank and supplying this solution to the rust-proofing tank at different :.-points so that the solution therein willbe r4 gipraotically uniform.

This process further consists in paxing the articles to be treated through the rustproofing bath at a constant speed at the same time turning over the articles while sub- I merged.

' In the accompanying drawing which illustrates conventionally a device for carrying out this process, Figure 1 is a side elevation of this apparatus, with the sides of the tanks removed. Fig. 2 is a section on the line 22 of Fig. 1.. Fig. 3 is a perspective of a re- 4 co tacle for the articles to be treated.

im-il'ar reference characters refer to like parts throughout the several views.

. The treating tank 1 which contains the rust-proofing bath may by steam coils 2 and with-tracks. 3- onflvhich the cylindrical containers 4 may-"travel, Short shafts 5 at the'ends of the oontain'ersmay enter the pockets 6 in the rims 7 of the double wheel 8, which maybedriven by means of a worm wheel 9, worm 10, shaft 11 and pulley It will be understood that D. CoLQ HoU'N, a'citizen of the United States, and residing at Detroit, in the county of Wayne and" State of Michigan, have invented. a new and stren bath becomes exhausted this construction is merely illustrative and that any other desired type of tank and conveying mechanism may be used.

The containers 4 may roll on'the tracks 3 and in'so do' turn the articles therein over and over whic is of great value as the rustproofing action is usually much more active on the upper side than on the lower side of the articles, being treated.

The, mixing tank 14 is preferably placed higher than the treating tank and in it are placed the phosphoric acid, manganese dioxid, water and such other materials as are employed to produce the solution. The pro portions of the acid and manganese may be those specified by the Richards Patent No.

1,069,903, dated August 12,1913. A- pipe .of the tank. 'The rate of flow from one tank to the other is substantially the rate of evaporation from the tank 1 so as to keep the bath at substantially constantlevel. The of the solution flowing to the tank 1 wil depend upon the rate at which the evaporation. I

In order to prevent the sediment in the mixing tank. 14 from flowing to the treating tank a short piece 17 of rubber tubing may he slipped onto the upper end of the pi e 15 and a short pipe '18 inserted into the ru her.

'A float 19 will keep the inlet end of this iihi s tank so that this solution can fiow.

quietly into this pipe without disturbing thel sedimentin the bottom of the tank. As no solid matter will be placed. in the tank 1, the amount of sediment which will accumulate therein will be very small.

and the rate of near. the surface of the solution 20 in the time is further reduced by turning over the articles being treated.

I claim:-

. I 1. The process of treating articles of iron and steel to prevent rusting which consists insubmerging them in a bath com rising, a compound of phosphorus to whic is con-' stantly added a similar compound of phos and steelto spaced points a similar phorus 1n more ooncentra the bath at maximum activity.

2. The process of treating articles of iron prevent rusting which consists in submerging them ina bath comprising keep the hos horus in solution to y a ded at a plurality of 00 pound of'phos I (1 solution to bath at maximum activity.

constan 3'. Theprooessof treating articles of iron and steel to prevent rusting: which consists in submerging them in a bathcomprising a compound of .phosp'horusfin' solution, heat-"- ing the bath and oonti'n'fially dding the same compound of phosphorus in a more concentrated solution to compensate for the evaporation and to keep the bath at maximum aotivity.

' ROY D. COLQUHOUN. 

